I was bleeding the brakes on my 58 tr3 with the bridge pipe and thought I would install those zerks with the check valve inside. They fit the threads fine, but I could not get them to seat at the bottom. The only differences I can see is the hole on the original zerks are higher on the shank and it appears the hole in the caliper has step down on it at the tip. I have used those new type zerks on the later calipers with no problem. Has anyone experienced this?